Yeah while MS does also "own" the PC ecosystem via Windows, I'd bet MS probably makes more money off of an individual Xbox player than a PC player which should make them a bit less friendly to PC.

For starters:

• Steam takes a 30% cut of all sales
• Sales and prices are usually much better on Steam than consoles so a lot of people wait for that number to drop over time
• For most multiplayer games you need to pay for Xbox Gold which is upwards of $50-$60 a year (or gamepass which is even more, though you get more out of it).
• You have to buy the console (this really depends on if MS actually makes money on console sales though) to play the game too.

Microsoft doesn't have to put their games on PC if they don't want to and in the past they kind of didn't (no one liked GFWL). They could totally go the exclusive route again, but I think MS knows that Xbox die-hard will buy an Xbox console and obviously buy the games on the xbox store for whatever it cost. PC players will also buy it if it's a good game and a good price and, this is crucial, is on Steam.

PC players are an untapped resource of potential customers; That's why Sony finally decided to also cave and put their games on Steam. Money is money, but the difference is MS is betting big on GamePass and good-will right now since they are behind Sony in sales. I think because they're behind Sony and trying to earn that good-will back, MS becomes more friendly to PC by putting their games on PC day one and on GamePass day one whereas Sony is still going with the 1-year (or more) PS5 exclusivity thing.

The interesting thing will be if MS ever gets back on top again, who knows what that looks like, but it'll probably suck.